DOUBLY CURVED SURFACES MODELING FONTYS ACADEMY of ARCHITECTURE

DOUBLY CURVED SURFACES MODELING FONTYS ACADEMY of ARCHITECTURE, TILBURG Giulio Piacentino 2008 mail@giuliopiacentino. com

PROJECT WORKFLOW software used in current architectural discourse MESH, NURBS POINTS, LINES, MESH NURBS, MESH, SUBDIVS MESH

WORKSHOP SCHEDULE Nov 28 Dec 5 morning 2 D/3 D interface patterns curves Complex surfaces manipulate solids afternoon surfaces construction your project help with choices Intro, paper model Solids modeling

Before we start: feel free to stop me whenever you feel it is necessary or you don’t have everything clear!

THE RHINO INTRO

INTERFACE

INTERFACE You can give instructions to Rhino by: menu items, command line and buttons.

For architectural practice: use the meter modelspace with small objects (recommanded), or the centimeter modelspace with large objs. Thirdly, mm (large).

INTERFACE Construction planes (Cplane) are view-dependent (one in each window) GLOBAL: symbols LOCAL: X is RED and Y is GREEN Z through right-hand rule

SHORTCUTS F 1 (help) F 2 (command. History ) Alt -temporarily disable o. Snap -copy object instead of drag F 3 (properties) F 6 (show camera) Ctrl -elevator mode F 8 (ortho) F 10 (points. On) F 11 (points. Off) Shift -temporarily toggle ortho

GEOMETRICAL BASICS

POINTS AND LINES points and straight lines are the easiest set of objects in rhino points can be grouped into point. Clouds lines can be joined into polylines are still MANY lines.

POINTS AND LINES points point. Cloud point. Grid drape. Pt

POINTS 0, 0, 0, 10 0, 0, 20 0, 0, 30 0, 0, 0 r 0, 0, 10 When you give coordinates , you can add an r to make the coordinate relative to the last given point.

CURVES curves are renders of mathematical equations curves in rhino are NURBS curves (Non-Uniform Rational B-Splines) they have: a degree they have: control points they have: weights

CURVES draw 3 or more curves with the same control points and different degrees.

CURVES you get a straight line after… as many points edit point in a row as the degree of the curve.

CURVES If we use any third degree NURBS curve, and we modify any set of points, the first curve segment to coincide again will be the one between the 2 nd-last and the 3 rd last modified point. After that, all will coincide again.

CURVES If the curve has kinks, you can explode it into smaller parts Otherwise you can divide it with split

CURVES You can join them back together, with Join, but they will be transformed into poly. Lines and poly. Curves (depending on the degree). Try the command Properties to inspect the outcome.

CURVES In some situations we may need to rebuild these polycurves, so that they can return to be a single entity. A similar command to try is also rebuild. Crv. Non. Uniform. Both these commands reconstruct selected curves or surfaces to a specified degree and with a specified number of control points.

CURVES Not always it is easy to rebuild a curve to something similar, if we don’t add many more points.

IN A INSTANT

SURFACES

SURFACES besides points and curves, NURBS surfaces are the basics of geometry in Rhino and can be used to draw both flat things and objects edge rve u oc is An isoparametric curve (isocurve) is a curve of constant u- or v-value on a surface. Rhino uses isocurves and surface edge curves to visualize the shape of a NURBS surface. By default isocurves are drawn at knot locations. If the surface is a single knot-span surface like a simple rectangular plane, isocurves are drawn also in the middle of the surface.

SURFACES v u NURBS are inherently rectangular (U / V) also surfaces can be rebuilt.

SURFACES Platonic solids and regular surfaces default. solid toolbar some of these commands create singular surfaces

SURFACES curvature analysis of some singular NURBS surfaces

SURFACES zebra (to visualize position, tangency and curvature continuity) write help for more information about it

SURFACES dir (to visualize and change direction of orientation), with crvs & srfs solids always have the normal toward the interior. flip directly turns the direction of crvs and srfs.

SURFACES 10 basic methods of surface creation in Rhino Srf. Pt corner points Extrude. Crv one curve and (one size)* Revolve profile (crv) axis (2 pts) Sweep 1 rail (crv) profile (crv) Loft sections (curves) Edge. Srf 2, 3, 4 edge curves Blend. Srf two surfaces Rail. Revolve Sweep 2 rail 1 (crv) rail 2 (crv) profile (crv) Network. Srf * More options of input are available rail (curve profile ) (crv axis) 4 or more crvs

SURFACES trim will cut the surface. But the control points remain.

SURFACES in some exceptional cases, we can use the command shrink. Trimmed. Srf. splitting along an isocurve will also automatically shrink the surface.

TRANSFORM TOOLS If you are familiar with any modeling software, you’ll find out that you can guess what each of these buttons will do.

VARIOUS OTHERS in the next exercises you might find also the following other commands useful: - divide a curve - offset a curve - project (parallel) onto a surface - pull a curve onto a surface - extrude. Srf to solidify a surface (straight movement) - offset. Srf to solidify a surface (parallel movement)